Propionibacterium

Propionibacterium
Propionibacterium acnes
Scientific classification
Kingdom:	Bacteria
Phylum:	Actinobacteria
Class:	Actinobacteria
Order:	Propionibacteriales[1]
Family:	Propionibacteriaceae
Genus:	Propionibacterium
Species
Propionibacterium acidifaciens Propionibacterium acidipropionici Propionibacterium acnes Propionibacterium australiense Propionibacterium avidum Propionibacterium cyclohexanicum Propionibacterium freudenreichii subsp. freudenreichii Propionibacterium freudenreichii subsp. shermanii Propionibacterium granulosum Propionibacterium jensenii Propionibacterium microaerophilum Propionibacterium propionicus Propionibacterium thoenii and others[2]

Propionibacterium is a Gram-positive, rod-shaped genus of bacteria named for their unique metabolism: They are able to synthesize propionic acid by using unusual transcarboxylase enzymes.^[3]

Its members are primarily facultative parasites and commensals of humans and other animals, living in and around the sweat glands, sebaceous glands, and other areas of the skin. They are virtually ubiquitous and do not cause problems for most people, but propionibacteria have been implicated in acne and other skin conditions.^[4] One study found the Propionibacterium was the most prevalent human skin-associated genus of microorganisms.^[5]

Members of the genus Propionibacterium are widely used in the production of vitamin B₁₂, tetrapyrrole compounds, and propionic acid, as well as in the probiotics and cheese industries.^[6]

The strain Propionibacterium freudenreichii subsp. shermanii is used in cheesemaking to create CO₂ bubbles that become "eyes"—round holes in the cheese.^[7]

References

1. Madigan, Michael T (2012). Brock: Biology of microorganisms (13th ed.). p. Apendix 2 page 12.
2. "Propionibacterium". National Center for Biotechnology Information (NCBI).
3. Cheung, Y.F., Fung, C., and Walsh, C. "Stereochemistry of propionyl-coenzyme A and pyruvate carboxylations catalyzed by transcarboxylase." 1975. Biochemistry 14(13), pg 2981.
4. Bojar, R., and Holland, K. "Acne and propionibacterium acnes." 2004. Clinics in Dermatology 22(5), pg. 375-379.
5. Rust, Susanne (4 February 2012). "UC Berkeley Bacteria Study: Research Shows Humans A Major Source Of Germs". Huffington Post (San Francisco). Retrieved 2012-04-06.
6. Kiatpapan P., Murooka Y. Genetic manipulation system in propionibacteria. Journal of Bioscience and Bioengineering. 93 (1) (pp 1-8), 2002
7. Making Swiss Cheese - David B. Fankhauser, Ph.D.